Friction or tractive drive fluid comprising adamantanes

ABSTRACT

A FRICTION OR TRACTIVE DRIVE COMPRISES AT LEAST TWO RELATIVELY ROTATABLE MEMBERS IN TORQUE TRANSMITTING RELATIONSHIP, THE TRACTIVE SURFACES OF THE MEMBERSHAVING DISPOSED THEREON ONE OR MORE TRACTANTS SELECTED FROM AT LEAST ONE OF THE FOLLOWING GROUP(1) OR (2): (1) ATRACTANT COMPRISING ALKYLATED ADAMANTANE HYDROCARBON HAVING ONE ADAMANTANE NUCELUS PER MOLECULE WITH THE C3-C20 ALKYL MOIETY AS A BRIDGEHEAD SUBSTITUENT; AND, (2) BIS-TYPE HYDROCARBON PRODUCT HAVING TWO ADAMANTANE NUCLEI LINKED BETWEEN BRIGEHEAD POSITIONS THROUGH THE C3-C20 ALKYLENE MOIETY.

United States Patent O 3,645,902 FRICTION OR TRACTIVE DRIVE FLUID COMPRISING ADAMANTANES Irl N. Duling, West Chester, Frederick P. Glazier, Thornton, and David S. Gates, Swarthmore, Pa., and Robert E. Moore, Wilmington, Del., assignors to Sun Oil Company, Philadelphia, Pa.

No Drawing. Filed Nov. 14, 1969, Ser. No. 876,993 The portion of the term of the patent subsequent to Aug. 3, 1988, has been disclaimed Int. Cl. C09k 3/00 U.S. Cl. 252-73 11 Claims ABSTRACT OF THE DISCLOSURE CROSS REFERENCES TO RELATED APPLICATIONS The present application is copending with the following listed applications, all of which are assigned to the Sun Oil Company, to whom the present application is also assigned:

(1) Rounds, F. 6., US. Pat. No. 3,394,603, dated July (2) Hamman, W. C. and Schisla, R. M., US. Pat. No.

3,411,369, dated Nov. 19, 1968 (3) Hamman, W. C. and Schisla, R. M., US. Pat. No.

3,440,894, dated Apr. 29, 1969 (4) Rounds, F. G., J. of Chem. and Eng. Data, vol. 5,

No. 4, pp. 499-507 (October 1960) (5) Hewko, Rounds and Scott, Proceeding of the Symposium on Rolling Contact Phenomena, pp. 157-185, Elsevier Publishing C0,, Amsterdam (1962) (6) Almen, I. 0. US. Pat. No. 2,045,555

(7) Hewko, Roller Traction Drive Unit for Extremely Quiet Power Transmission, AIAA Paper 67-429 Applications of Irl N. Duling, David S. Gates and Robert E. Moore, Ser. No. 679,801, filed Nov. 1, 1967 and Ser. No. 3,256, filed Aug. 19, 1969, are directed to the use of adamantane compounds as traction fluids or as components of traction fluids.

SUMMARY OF THE INVENTION A friction or tractive drive comprising at least tWo relatively rotatable members in torque transmitting relationship, the tracti've surfaces of said members having disposed thereon a tractant comprising at least one member selected from at least one of the following groups (1) or (2):

( 1) alkylated adamantane hydrocarbon having one adamantane nucleus per molecule with the C -C alkyl moiety as a bridgehead substituent, more preferably, alkyladamantane hydrocarbon material represented by QX wherein Q is a C C alkyladamantyl group with a. bridgehead valence selected from dimethyladam antyl, trimethyladamantyl, ethyladamantyl, methylethyladasyggisetic Lubricants From Low Molecular Weight 01efins-Riohard S. Stearns, Irl N. Duling and David S. Traction Drive Transmission Containing Adamantane Compounds as LubricantIrl N. Duling, Frederick P.-

Traction Drive Transmission Containing Napthenes, Branched Paraffins, or Blends of Napthenes and Branched Blending Branched Paraffin Fluids for Use in Traction Drive Transmission1rl N. Duling, David S. Gates Catalytic Hydrofinishing of Petroleum Dlstillates in the Lubricating Oil Boiling Range1vor W. Mills, Glenn R.

Hydrorefined Lube Oil and Process of Manufaeture1vor W. Mills and Glenn R. Dimeler.

Reaction of Alkyladamantane Compounds to Form Products Having Two Linked Adamantane Nucle1-R0b- Friction or Tractive Drive FluidIrl N. Duling, Frederick P. Glazier, David S. Gates and Robert E. Moore.

Serial No. Filing date Title Glazier, David S. Gates and Robert E. Moore. 679,833 11-1-67 Parafiins as Lubricant-Irl N. Duling and David S. Gates. 679,834 11-1-67 and Thomas D. Newingham. 784,487 12-17-68 Conversion of Adamantane Hydrocarbons to MonoolsRobert E. Moore. 794,844 1-24-60 Friction Drive FluidIrl N. Duling, and Frederick P. Glazier. 812,516 2-19-69 Dimeler, Merritt C. Kirk, J r. and Albert '1. Olenzak. 823,138 5-8-69 Reaction for Linking Nuclei of Adamantane Hydrocarbons-Abraham Schneider. 850,717 8-18-60 851,488 8-19-69 ert E. Moore and Abraham Schneider. 3,258 8-19-69 877 004 11-14-69 Reaction of Normal Paraflins with Adamantane Compounds"-Robert E. Moore.

1 The present application is a continuation-in-part of these two applications.

The disclosure of all of the above-referred to applicamantyl and dimethylethyladamantyl and X is a C -C BACKGROUND OF THE INVENTION Friction or traction drive systems for the transmission of power and testing equipment for determination of the traction coefiicient have been described in numerous prior art references. See, for example, the following:

alkyl group terminally attached at said valence and at least predominantly of the structure wherein n is an integer of 1 to 17, and

(2) bis-type hydrocarbon product having two adamantane nuclei linked bet-ween bridgehead positions through the C -C alkylene moiety.

These admantanes can be obtained by means disclosed in the previously referred to application of Robert E. Moore, filed of even date with the present application.

As can be seen from the previously cited references, special properties are required of the traction fluids used in friction drive systems. One desired property is a high coefficient of traction as measured for example, by the test procedure described in reference (4) supra. As shown therein, most materials have traction coeflicients (measured at 200 R, 400,000 p.s.i. and at a bearing speed. of 600 ft./min.) less than 0.06, with the values for hydrocarbons usually falling in the range of 0.03-0.05. In comparison, alkyladamantanes and bis-type products of the previously-referred to application of Moore and Schneider (including the ethers as well as the hydrocarbon dimers) generally have traction coeflicients measured in this manner in the neighborhood of 0.06 or higher. They are thus particularly valuable as traction fluids or as additives for improving the traction coefficients of known types of traction fluid compositions. The products which are liquid at room temperature and atmospheric pressure are preferred for this purpose, but those which are normally solids also can be used to the extent that they are substantially soluble in the base fluid at the temperatures and pressures at which it is required to operate in the friction drive system.

Especially useful traction fluids comprise from -95 by volume of one or more such alkyladamantanes or bistype hydrocarbons of the Moore application and from 95-5 of an acyclic branched chain fluid polymer of a C -C monoolefin, said fluid polymer having, preferably, a SUS viscosity at 100 F. in the range of -20,000 SUS, and, more preferably, at ASTM viscosity index in the range of -160. Preferably, the final, blended traction fluid has an SUS viscosity at 100 F. in the range of 30-15,000.

FURTHER DESCRIPTION As is disclosed in the above-referred to copending application of Robert E. Moore saturated adamantane hydrocarbons of the C -C range having 0-3 alkyl substituents and/or their corresponding adamantanols are reacted with n-paraffins of the C -C range by contacting a mixture of such reactants with sulfuric acid having a strength of 96-102% H 50 equivalent at a temperature between the freezing point of the acid and 100 C., more preferably l0-75 C. This causes a C -C alkyl or alkylene moiety, derived from and having the same number of carbon atoms as the n-paraffin used, to become attached to the adamantane nucleus. As a result, two types of products are obtained: (1) alkylated adamantane hydrocarbon having one adamantane nucleus per molecule with the C C alkyl moiety as a bridgehead substituent; and (2) bis-type hydrocarbon product having two adamantane nuclei linked between bridgehead positions through the C -C alkylene moiety. Generally, both types of product can be produced in substantial yields. They can be recovered in admixture with each other, such a mixture being particularly useful as a tractant or a component of a tractant for a friction or tractive drive.

Preferred products for use as a tractant or in tractant blends are those made from C -C n-paraflins and C -C alkyladamantanes or alkyladamantanols in which the alkyl substituents are methyl and/or ethyl.

Preferred adamantane reactant material for producing tractants by the process are the alkyladamantane hydrocarbons of the C -C range having one, two or three alkyl substituents, or their monools. The presence of alkyl groups on the nucleus of the feed material usually tends to reduce the solidification point of the resulting products and give them wider utility in traction fluid applications. The most preferred alkyladamantane reactant compounds are the hydrocarbons of the C -C range and particularly the following: dimethyladamantanes, trimethyladamantanes, ethyladamantanes, methylethyladamantanes and dimethylethyladamantanes. Some specific examples of these and other hydrocarbons that can be used are as follows: adamantane; 1 methyladamantane; 2 methyladamantane; 1,2-, 1,3- and 1,4-dimethyladamantane; 1- and Z-ethyladamantanes; l ethyl 3 methyladamantane; 1 ethyl 4 methyladamantane; 1,2,4-, 1,2,5-, 1,3,4- and ,3,6 trirnethyladamantanes; 1 ethyl 2,4-dimethyladamantane; and 1 ethyl 3,6 dimethyladamantane. Illustrative examples of other starting hydrocarbons containing higher alkyl groups are: land 2-butyladamantanes; 1 methyl 3 propyladamantane; 1,3-dimethyl- 5 butyladamantane; 1 ethyl 2 methyl S-hexyladamantane; 1 pentyl 4 methyladamantane; 1,3-diisobutyladamantane; n-hexyladamantanes; n-nonyladamantanes; and the like.

Any adamantanol corresponding to the hydrocarbons as above defined is also suitable as reactant material. The hydroxy group can be located at either a bridgehead or nonbridgehead position on the nucleus. Substantially the same results will be obtained regardless of the original position of the OH radical on the nucleus, inasmuch as immediate isomerization of the -OH to an unsubstituted bridgehead position on the nucleus occurs in the presence of the strong sulfuric acid used in the process.

The other reactant in the process is a normal paraflin hydrocarbon of the C -C range. Whereas the n-paraflins themselves in the presence of strong sulfuric acid are normally inert, they become quite reactive when the adamantane compound is also present and can readily function as an agent for alkylating the adamantane nucleus. Any normal paraffin ranging from propane to eicosane or any mixture of these n-parafiins can be used in the process. When a higher molecular weight n-paraifin of the group herein defined is used, a reaction temperature in the upper part of the herein specified range preferably is employed. For preparing material for use in traction fluid compositions, n-parafiins of the C -C range are particularly suitable reactants. One useful mixture of C -C n-paraflins is obtained by separation of n-paraflins from virgin or straight-run gasoline by means of molecular sieve adsorbents.

.Reaction of the adamantane hydrocarbon or monool feed material with the n-paraffin in accordance with the invention is effected by contacting a mixture of these reactants with strong sulfuric acid. The molar ratio of the adamantane compound to the n-parafiin can vary widely in the reaction mixture but usually will be in the range of 3:1 to 1:10. The ratio of acid to reactants can vary widely. Generally a volume excess of the acid relative tothe reactants should be used and a volume ratio thereof in the range of 1:1 to 20:1 typically is employed. The mixture normally is an emulsion of acid and hydrocarbon phases, and the reaction takes place in the acid phase. The sulfuric acid should have a strength in the range of 96-102% H equivalent by weight and more preferably 97-101 H 50 The reaction temperature can be from just above the freezing point of the acid used to about 100 C. and usually is in the range of 10-75 C. When a lower alkane such as propane or butane is used as reactant, the reaction is conducted under suflicient pressure to maintain a substantial concentration of the alkane in the liquid phase.

EXAMPLES As a specific illustration of the invention, the reaction of n-pentane with 1,3-dirnethyladamantane (DMA) is considered. This reaction is effected, for example, by contacting a mixture of D-MA and n-pentane in a molar ratio of 1:2 with sulfuric acid having a strength of 100% H 50 at 50 C. for 10 hours. The acid and hydrocarbon layers are separated, the hydrocarbon layer is washed with water or aqueous alkali to remove residual acid, and the hydrocarbon material is then fractionally distilled to recover the products. The alkyladamantane product upon analysis is found to be composed mainly of the following (hydrogen atoms omitted for convenience):

Specifically this product is l,3-dimethyl-5-(3-methylbutyl) adamantane. Smaller amounts of isomeric product with the methyl branch in the C alkyl substituent positioned closer to the adamantane nucleus may also be produced, but the predominant isomer formed is the one shown. No isomer having an n-pentyl group is detected. A higher boiling bis-type product is also obtained and the major part thereof is found to correspond to the following structure:

This compound specifically is 1,4-bis(3,5-dimethyladamantyl-l)-4-methylbutane. A minor amount of product which boils closely to this compound and appears to be isomeric thereto generally is also produced.

A blend is made of 60 volume percent of the abovereferred to isomer mixture and 40% of a substantially fully hydrogenated polybutene polymer. The traction coeflicient (by the Rounds method) at 600 ft./min., 400,000 p.s.i. and 200 F. is 0.059. This 60/40 blend also has good oxidation stability compared with the hydrogenated polybutene, good fluid properties and a greatly decreased tendency to foam when used in a traction drive.

Similarly, when the feed paraffin in the above reaction is n-hexane instead of n-pentane, the product of the re action comprises a mixture of l,3-dimethyl-5-(4-methyl' pentyl)adamantane and 1.4 bis(3,5-dimethyladamantyl' 1)-5-methylpentane. The traction coeflicients (at 60 ft./ min., 400,000 p.s.i. and 200 F.) for these individual compounds are 0.060 and 0.061, respectively.

When the feed paraffin is n-butane, the product of the reaction comprises a mixture of 1,3-dimethyl-5-(Z-methylpropyl)adamantane and 1,4 bis(3,5-dimethyladamantyl- 1)-3-methylpropane. This mixture and these individual components are good tractants, especially when blended with C -C polymer oils (or hydrogenated C -C polymer oils).

When a monool of DMA is used instead of the hydrocarbon, the same two hydrocarbon compounds as shown above are again obtained as the major products regardless of the original position of the hydroxy group on the nucleus. However, the reaction tends to proceed to completion more rapidly when the starting adamantane compound is a monool instead of the hydrocarbon.

It is characteristic of the main products of the Moore process that, for any of the n-paratfins except propane, the alkyl and alkylene groups derived from the n-parafiin each will have a single methyl branch. Furthermore the methyl substituent in the alkyl group will be attached mainly to the second carbon adjacent the unattached end of the chain, while that in the alkylene group will be attached mainly to an alpha carbon atom in the chain. In other words, the alkyl and alkylene groups in the main products of the reaction will conform, respectively, to the following arrangements:

C In When n-paraffins of the C -C range are used as reactant, n and m in these formulas would be integers which are, respectively, 1 to 5 and 2 to 6. The presence of the methyl substituents in the alkyl and alkylene moieties of the reaction products is beneficial for utilization of the products as components of traction fluids, as the methyl branches tend to prevent crystallization and lower the solidification of pour points of the products.

Both types of alkylation products are usually obtained from the present reaction, but the proportions thereof can vary considerably depending upon the particular reactants and conditions selected. As a general rule, formation of the bis-type product relative to the alkyladamantane is favored by higher acid concentrations and higher temperatures and by using a monool reaction instead of the adamantane hydrocanbons as feed material.

From the present process when utilizing one or more 0 -0 alkyl-adamantanes or al kyladamantanols and one or more C -C n-parafiins, a particularly desirable mixture can be recovered composed of a combination of the two types of alkylated adamantane products as above described. This constitutes a novel composition which has outstanding utility as a component of traction fluids. Both types of reaction products have unusually high traction coefficients as compared to most hydrocarbons. Also the fact that the mixture involves a plurality of hydrocarbons containing adamantane nuclei is advantageous, since the pour point is reduced and an intermediate viscosity level desirable for various traction system applications is secured.

This novel composition suitable as a traction fluid component can be defined as a mixture of hydrocarbons containing adamantane nuclei and composed of a combination of the following:

( 1) alkyladamantane hydrocarbon material represented by QX wherein Q is a C -C alkyladamantyl group with a bridgehead valence selected from dimethyladamantyl, trimethyladamantyl, ethyladamantyl, methylethyladamantyl and dimethylethyladamantyl and X is a C C alkyl group terminally attached at said valence and at least predominantly of the structure wherein n is an integer of 1 to 17, and

(2) bis-type alkyladamantane material represented by QZQ wherein Q is as previously specified and Z is a C -C alkylene group linking the Qs bet-ween bridgehead positions and at least predominantly of the structure wherein m is an integer from 2 to 18.

Many of the 'alkyladamantane and bis-type products produced by the Moore process are oils at room temperature and exhibit unusually high traction coeflicients. They are particularly useful as components of traction fluids for use in friction drive or toric transmission systems. Some of the products (in pure form) have sufiicient symmetry to be relatively high melting solids, and these can have utility as components in traction fluids containing a solubilizing agent, such as a fluid naphthene hydrocarbon, or a fluid branched paratfin or olefin acyclic hydrocarbons or a mixture of naphthene and acrylic hydrocarbon's.

Suitable components for blending with the alkylada mantanes of the Moore application, in order to produce improved, blended traction fluids are those oils prepared by polymerization of olefins, hydrogenated polyolefin oils (particularly when substantially free of olefinic unsaturation), hydrogenated hydrocarbon oils and saturated cyclic and acyclic hydrocarbons described in the above-referred to copending patent applications Ser. Nos. 679,801; 679,- 833, 679,834; 679,851 and 794,844. Particularly useful fluids for such blending are (1) hydrogenated naphthenic or parafiinic oils containing no more than 1 weight percent of gel aromatics, (2) C -C organic liquids having at least one saturated ring and having a coeflicient of traction of at least 0.06 as defined in US. Pat. No. 3,440,- 894, (3) a fused saturated component having from 2 to 9 fused rings and a total carbon content of from about 9 to about 60 as described in US. Pat. No. 3,411,369, (4) liquid hydrocarbon having an acyclic structure with at least three quaternary carbon atoms, as described in US.

Pat. No. 3,440,894, members of groups (2) to (4) inclusive wherein up to 8 carbon atoms are replaced by atoms selected from the group consisting of oxygen, nitrogen, phosphorous =and silicone (e.g., see US. Pat. No. 3,411,369 and US. Pat. No. 3,440,894). Fluorinated compounds corresponding to any of the above-referred to adamantane compounds wherein from l-all of the hydrogen in the hydrocarbon has been replaced by fluorine are also useful as traction fluids or as components of traction fluids, particularly in blended fluids with hydrogenated olefin polymers.

The invention claimed is:

'1. In a friction or tractive drive comprising at least two relatively rotatable members in torque transmitting relationship and a traction fluid, the improvement wherein, the tractive surfaces of said members have disposed thereon a traction fluid consisting essentially of a member selected from the following groups (1) or (2):

( 1) alkyladamantane hydrocarbon material represented by QX wherein Q is a C C alkyladamantyl group with a bridgehead valence selected from dimethyladamantyl, trimethyladamantyl, ethyladamantyl, methylethyladamantyl and dimethylethyladamantyl and -X- is a (L -C alkyl group terminally attached at said valence and at least predominantly of the structure OHz wherein n is an integer of 1 to 17, and

(2) bis-type hydrocarbon product having two adamantane nuclei linked between bridgehead positions through a C -C alkylene moiety. having the same number of carbon atoms and skeletal structure as X--.

2. A friction or tractive drive according to claim 1 and comprising a power input member and a power output member in tractive rolling contact relationship and a fluid film between said members, said fluid film consisting essentially of at least one member from said group (1) or said group (2) or mixtures thereof.

3. A drive according to claim 2 wherein said fluid film additionally contains from 955% by volume of a fully hydrogenated polymer of C -C olefin.

4. A drive according to claim 1 wherein said alkyl adamantane is selected from the following group:

1,3-dimethyl-5- B-methylbutyl) adamantane l ,3-dimethyl-5- Z-methylpropyl adamantane 1,3-dimethyl-5- (4-methylpentyl) adamantane 1 ,4-bis 3,5 -dimethyladamantyl-1 )-4-methylbutane 1,4-bis 3 ,5 -dimethyladamantyl-l )-3-rnethylpropane 1,4-bis (3 S-dimethyladam antyl-l -5-methylpentane 5. A drive according to claim 2 wherein said tractant consists essentially of a mixture of:

(1) alkyladamantane hydrocarbon material represented by QX wherein Q is a C C alkyladamantyl group with a bridgehead valence selected from dimethyladamantyl, trimethyladamantyl, ethyladamantyl, methylethyladamantyl and dimethylethyladamantyl and X is a C -C alkyl group terminally attached at said valence and at east predominanty of the structure wherein n is an integer of 1 to 5, and

(2) bis-type alkyladamantane material represented QZQ wherein Q is as previously specified and Z is a C C alkylene group linking the Qs between bridgehead positions and at least predominantly of the structure CH lon wherein m is an integer from 2 to 18.

6. A drive according to claim 5 wherein group (2), Z is a C -C alkylene group and m is an integer from 2 to 6.

7. A drive according to claim 3 wherein said tractant consists essentially of from 5-95% by volume of one or more of said alkyladamantane isomers of group (1) and from -5 of an acyclic branched chain fluid polymer of a C -C monoolefin, said fluid polymer having an SUS viscosity at F. in the range of 20-20,000 SUS and an ASTM viscosity index in the range of 30 to 160.

8. A drive according to claim 7 wherein said tractant has a viscosity in the range of 3015,000 SUS at 100 F.

9. A tractant composition consisting essentially of at least one member from the following groups (1) or (2):

(1) alkyladamantane hydrocarbon material represented by QX wherein Q is a C C alkyladamantyl group with a bridgehead valence selected from dimethyl-adamantyl, trimethyladamantyl, ethyladamantyl, methylethyladamantyl and dimethylethyladamantyl and X is a C C alkyl group terminally attached at said valence and at least predominantly of the structure CH A l wherein n is an integer of 1 to 17, and

(2) bis-type hydrocarbon product having two adamantane nuclei linked between bridgehead positions through the C -C alkylene moiety and from 955% by volume of a fully hydrogenated polymer of C -C olefin.

10. A tractant composition according to claim 9 wherein said member from group (1) is 1,3-dimethyl-5- 3-methylbutyl) adamantane 1,3-dimethyl-5- (Z-methylpropyl adamantane 1,3-dimethyl-5- (4-methylpentyl adamantane 1 ,4-bis 3,5 -dimethyladamantyl-1 (4-methylbutane 1,4-bis 3,5 -dimethyladamantyl-l -3 -methylpropane 1,4-bis(3,S-dimethyladamantyl-1)-5methylpentane wherein n is an integer of 1 to 5,

and said members from group (2) consist of: 3,203,186 8/1965 (2) bis-type alkyladamantane material represented by 3,208,946 9/1965 QZQ wherein Q is as previously specified and Z is 3,285,851 11/1966 a 0 -0 alkylene group linking the Qs between 3,382,288 5/1968 bridgehead positions and at least predominantly of 5 3,398,165 8/1968 the structure 3,411,369 11/1968 CH3 3,440,894 4/1969 \Tii wherein m is an integer from 2 to 18.

References Cited UNITED STATES PATENTS 10 Sheppard 6054.5 Anderson et a1. 25259 Dyer 252325 Schneider 260666 Duling et a1. 260-410 Hammann et a1 74-200 Hammann et a1. 74200 LEON D. ROSDOL, Primary Examiner 10 H. A. PITLICK, Assistant Examiner US. Cl. X.R. 

